Semiconductor devices, such as for example integrated circuits and micro-electro-mechanical systems (MEMS) devices, are packaged inside corresponding packages, which perform functions of protection and interfacing with the outside world. For example, packages are known that enable so-called “surface mounting” on a printed-circuit board.
In greater detail, surface-mount packages include, for example, packages of a “quad-flat no-leads” (QFN) type, also known as “micro lead frame” (MLF) packages or “small-outline no-leads” (SON) packages.
In general, a QFN package includes a region of resin on a lead frame, which forms at least one array of terminals that are exposed by a bottom surface of the package.
Small dimensions and good electrical and thermal performance characterize QFN packages. However, it is frequently problematic to inspect and ensure that soldering on the printed-circuit board has been carried out properly. In fact, visual inspection of the welds present between the terminals and the corresponding pads of the printed-circuit board is hindered by the very arrangement of the terminals on the bottom surface of the package. U.S. Patent Application Publication No. 2005/0116321 by Felix et al., which is hereby incorporated by reference, describes a method for manufacturing a package in which the terminals are formed by punching in such a way as to present a recess facing the printed-circuit board. In this way, the terminals form a surface that remains exposed during the operations of application of the soldering paste. Further, the package is such that, when it is soldered on the printed-circuit board, corresponding soldering joints are present between the terminals of the package and the pads of the printed-circuit board. The soldering joints may be noted and inspected visually in a relatively easy way. However, the angle under which each soldering joint is visible is not particularly wide, nor is the weldable area of each terminal.
The present disclosure provides a package for a semiconductor device that solves, at least in part, the drawbacks of the known art.